Voltage or power regulators or converters are used in a variety of electronic circuits and can have a variety of different designs or architectures. A typical application for a power converter is to provide a variable electrical current at a relatively constant voltage level for normal operation of the electronic circuit.
There are times when a typical power converter must operate at a very low power level, i.e. in a standby mode, a low-load mode or a no-load mode. For example, when a cell phone is unplugged from its charger, the power converter in the charger enters the standby mode, in which it draws very little power. The charger continues to draw some minimum amount of power in order to maintain output voltage regulation and to be able to detect when the cell phone is plugged back into the charger. Upon detecting the cell phone, the power converter of the charger ramps up to a “normal” mode, in which it operates at a high, or normal, power level.
Many power converters may spend most of the time in the low-load, or standby, mode, e.g. when a charger (incorporating the power converter) is left plugged in to an AC wall outlet after a cell phone has been unplugged from the charger. However, the power used during this time is generally wasted. It is very important, therefore, for such power converters to draw as little power as possible during this time in order to minimize power wastage and maximize efficiency.
It is with respect to these and other background considerations that the present invention has evolved.